Fox T-Bird/Cougar Forums  

Somebody named "alex" will be calling me back today hopefully on these gems.  Ill try to get pricing as well.

I think i like it!!

If it seems like I've put a lot of thought into this, it's because I've been thinking about alternatives to the current cam/lifter/valve setup since middle school (we're talking early 80's here). I would sit in class and daydream about ways to elimimate the cam and use solenoids. Solenoids would allow infinitely variable valve lift, duration, and overlap. It could be changed on the fly and cylinder-to-cylinder. The throttle blade could be eliminated entirely, since you could throttle the engine by only opening the valves enough to let enough air in to idle.

Strangely enough, in my mind I could never overcome the valve closing problem with solenoids, either. If I used springs in my imaginary cylinder head the solenoids would have to be extremely strong (meaning large, heavy, and really sucking down the current) in order to overcome spring pressure and open the valves. If I didn't use springs the solenoids could be smaller, but they would close the valves too hard (unlike a traditional cam, which closes the valve gently as the lifter rides down the back side of the lobe, a solenoid would whack it closed suddenly). This would lead to the "tuliping" problem I mentioned above.

Even stranger, though, is that after a few moments thought I think I may have come up with a solution for the Decuir springless valve system. Install a shock absorber on each valve. It would not have to be a big shock with a lot of range of motion, just something with a few thousandths of an inch that allows just a bit of "stretching" between the valve seat and the camshaft. Perhaps a solid rubber block inside the "shock absorber" that would compress ever so slightly when the valve closed, yet rebound (again, ever so slightly) when the valve is open again. This would allow the valves to be pulled fully closed without stressing metal components. Here's a quick drawing of my idea:


Of course this idea opens itself to a whole new slew of problems. Aside from the extra weight (which would mean more inertia, which would make the engine more resistant to revving), I can't for the life of me see how you'd get this valve into the head. I drew it fully assembled, so just imagine trying to disassemble it :hick:

Why not use hydraulics like the hydralic lifters for the shock absorber?

your right,, i jumped right to the true link system.  That is what i thought the topic was about and did not notice the lifter to cam relationship as its designed.

I like your visio or whatever drawing, and i grasped the concept you needed to spend time on about absorbing the shock of the valve closing.  We talked about this a couple of years ago and i asked you why not reverse the polarity of the solenoid to close it,,, of course this does not solve DC power consumption but it does close the valve without a spring.  I cant computate what seat presure there would be but it would close the valve nonetheless.  I really dont think a valve has to "look" like the cookie cutter valve we see everyday but something new and different such as a port / door / round flat disc moving in view and out of view allowing air/fuel in and closing on reverse polariity.  basically the door or port would reside parallel with the the visible surface of the piston.  There are many electrically activated check valves out there that are low current and used as safety cutoff valves for many industrial applications.

VALEO Engine Management Systems has, since 1998, been working on an infinitely variable valve actuation system based on a linear spring-mass actuator. The VALEO electromagnetic variable valve actuation system replaces the intake camshaft with electromagnetic valve actuators that are driven by a Valve Control Unit (VCU).

The Valeo system uses electromagnetic actuation. Where a typical valvetrain uses a spring to hold the valve closed until the camshaft lobe overcomes the spring, the camless system uses a pair of springs, and the valves default to a partially open position. There's a pair of electromagnets above the valve assemblies with an armature in between. The armature is what the electromagnetic fields move to actuate the valve. The upper electromagnet pulls the valve shut, and the lower electromagnet fully opens the valve. This system eliminates entirely the camshaft and its associated drive system such as belts, tensioners and bearings. High performance engines with variable timing and lift valvetrains will be easy to accomplish with the Valeo system, as opposed to the complex mechanical systems currently used to accomplish those functions. Think of Valeo's system as operating much like a fuel-injection system. Each valve event can be discrete and optimized. Low end torque will be increased, and cylinder head design can use more radical valve and port angles without having to fit rotating machinery above and around the cylinder head. Depending on the size of the hardware, packaging could approach the compact size of pushrod engines.

Siemens

I didn't realize until I read the article that noise from slamming valves is a huge issue with these systems. Apparently Siemens has a system to get the valve to near zero velocity (by carefully controlling current flow) as the valve closes - thus actually reducing noise and valve wear!!